Xdottble-sfring t tokb adjustment



Nov.

F. E. HULT DOUBLE SPRING YoKE ADJUSTMENT Filed Sepia. 5, 1919 l. @lauw llmwml a r I N VENTO R ffmyai Patented Nov. d, i924.

h"liililt ttitltt .tric E.

.application tiled september 3. seria] No. 321,436.

To all when@ :it may concern ie it known that li, ljntnr l-lionr, a citi non oi" the United titates, residing at @tooliton, in the county ot @an lloaipiin and @tato oi California, have inventckl. new and use tnl lmproven'iei in Double-t5ating ioke ilidjos nente, oi which the tollen/'ing is a :-;peo:iii :ation.

ijhie invention relates to tractors oit the chain track type, and incre particniarly to a mounting tor one ot the sprocket win-tels ot the chain track.

ln tractors ot this type the trontidler wheel, while being capalile ot adjustment npon the truckftfranie in a tore and att direction to take np slack occurring in the track, this adjustment is always made by hand and is one req` ',ng a great deai ot eli'ort and time since the sprocket wheel innst be pushed ftnwardly against the tre inendous weight ot the track. fflilso this :rigid connection tor the sprocket wheel re eults sometimes in the breakageai ot the track where an unyielding obstruction talle upon the track and is carinii-,id by the lattininto contact with. the sprool-ret wheel.

In the present invention l'. have provided a mounting ifor one oit the sprocket wheels, such that the bearings thercot are 'treely slidable on the truck p freine and are hold in a :torwaii'd position by spriiig1n 'essod means, the pressure oit the spring on the sprocket wheel being sniiicicnt to maintain the chain track under the required tension at all times and yet being suiiicicntlyyielding to permit the sprocket wlieel to niovo inwardly in case an ul'iyielding obstruction is carried between the sprocket. wheel and track. 'llhereby l overcome the work ot :manually adjusting the position oi the sprocket wheel. to take up slack occurring in the track and. also in sure against breakage ot the track.

Referring to the accon'ipanying draw-- ings:

Fig. l shows a side elevation ot a tractm.' embodying n'ly iiiveiiition.

lTig. 2 shows a sectional view, taken on the line 2-2 otllig. l. y

Fig. 3 shows a sectional View, taken on the line 3"-8 oit liig. 1.

llig. 4f shows a inoditied torin oit the arrangement illustii'ated in Fig. 3.

The tractor herein shown comprises a i'nain tranne l0, at each side ot which is a truck mechanism made up ot a truck traine il, on which are Ajonrnaled supporting rollers l2 and at the l'orward end ot which is carried an idler sprocket wheel 13. A toothed sprocket wheel it is jonrnaled upon the inain :trarne and an endless chain track is carried by the toothed sprocket and the idler wheel, passing beneath. the rollers 12.

.ihe truck traine ll. herein shown is ot special construction employing steel side plates 16, spaced apart at their lower portions and brought into contact with each. other at their upper edges, whereby to enclose the upper portion ot the truck mech anisni. ji, guide rail 17 is termed at the upper edges ot the contacting side plates and serves as a support tor the upper run ot the chain track. The idler sprocket wheel "tizi is carried in bearings 18, said bearings being slidable in slots 19 formed by cutting the sido platos and pressing the cntportions outwardly to torni flanges 20.

lfn the usual type of' tractor et this nature the idler sprocket wheel 13 is carried on bearings which are slidable on the truck traine, such bearings being adapted to be sec d in a variety oi positions thereon so that the location ot 'the idler' sprocket wheel may be changed ttor the purpose ot taking np slack in the chain track or otherwise ad insti the tension oil the track.

rlthe operation tot shitting this idler sprocket; 'wheel against the tremendous weight oit the chain track is one requiring considerable eltort and time. ln the present invention the bearings tor the idler sprocket wheel are :freely movable in the slots i9 and a yoke 2l extends rearwardly troni said hearings and has a stein 22 which lits in a socket 23 and is slidable therein. This stein passes through a cylinder 24, tired upon the truck traine and within which cylinder is an extensible coil spring 25. The cylinder 2li has a movable head 26 at its rear end which serves as a pressure plate tor the spring 25, said movable head 26 being car ricd upon the stein 22 and abutting against the shoulder of the latter. The rear end oi the stein 22 is screw-threaded, as shown at 2'?, and carries a worm gear 28, which worin gear has a hub portion screw-threaded interiorly to cooperate with the screw-threaded portion ot the stein. 'lihe said worin gear is held against rearward Inoveinent oi the screw-threaded stein by means of a plate 29 lined to the truck tramo.

ltftnsifersely of lthev truck frame and journaled in opposite side platesis ,a

,slurft 30 oneendof which ,is fitted with an "aligiltar lifdfor n ketl, to receive a wrench 0r shaft'() has fired upon it a spiral gear 32 to cooperate with the worni gear 28.

In operation, the idler sprocket wheel is kept in forward position under the pressure ofathetrspring 25 and; is held yieldingly in .fsuhfip'ositon- Aiiyfslack occurringin the .chain track is automatically taken up by the 'aqtioniofgthesaidspring. Since the bearl, ,"ings forrftheidler sprocket wheel .are freely sl-idable on the truck frame it will be seen lthakt shouldfany obstruction fall upon the trackr' and become lodged between thetrack and eitherls'procket wheel, then this idler sprocket Wheel will be forced rearwardly, 'compressing the spring 25, and allowing the obstruction to pass through without danger of `breaking the track. When for any reason theiften'sion of the track becomes less than desired the spring can be further comipressed turniiigthe shaft from the exterionfof the y:truck fname.

In Fig; 4 Ihaveshown a modified form in twospiings 25 are employed, one on leachlegiof the yyoke 2l. The action of the modified formfisthesame as ythat already kdescribed. The -advantage vof the modified arrangement i'stopermit the use ofllighter springs, since twoare used in'placeof one.

l Inthi'spinoditied arrangement Ishow an adjustin b'olt'33 seated in the head of each of `'the cy inders 24 for the purpose ofindepend- 'cntly adjusting the tension ofthe springs 25.

Various changes inthe construction and arrangement Yof the several parts herein slfovvnand described may befemployed with- `out'olepartingfrom the spirit of my inventoward and from the idler sprocket, a thrust yoke having its arms extended on opposite sides of the idler sprocket and supporting the bearings of the idler s rocket against rearward noven'ient and at iltls rear end supported by the adjustable shaft and compression spring supporting means interposed between the idler sprocket bearings and the shaft.

2. In a tractor truck mechanisi'm-the conlbination with the truck frame having spaced side members, a rear sprocket wheel, a front idler sprocket, bearings for the idler sprocket movably mounted in the frame, and a flexible track tread passing around the sprocket wheel and idler sprocket, of a thrust support for advancing the idler sprocket and holding the track tread under tension, comprising a thrust yoke having forwardly extending arms connected with the bearings for the idler sprocket, means for holding the rear end of the yoke against transverse movement, a longitudinally ad- `instable shaft journaled in the frame between the rear and front sprockets, and cngagng the rear end of the yoke for advancing the yoke and idler sprocket, means for moving said shaft into fixed positions of longitudinal adjustment and yielding spring means interposed between the shaft and the bearings.

3. In a chain track truck mechanism, a truck frame, a sprocket wheel journaled thereon and having its bearings slidably connected thereto, a thrust member connect ed to the bearings, a spring included in said thrust member acting to yieldingly force the same forwardly, a. worm wheel on thc thrust member and a. screw shaft fixed to the frame and with which the worni wheel meshes.

4. In a chain track truck mechanism, a truck frame, a sprocket wheel journaled thereon and having its bearings slidably connected thereto, a thrust member connected to the bearings and adjusting connections between the thrust member and the frame comprising a worm wheel and a screw shaft.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

PLINY lil. HOL'V.

Vitnesses:

CHARLES L. NnUMiLLnn, DAVID B. LYMAN. 

